# LM2676S-3.3

**Texas Instruments** · DC-DC Converters · TO-263-7

LM2676S-3.3 from Texas Instruments, in a TO-263-7. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | Switch_output | output | Source pin of the internal high-side FET and the switching node; connect it to the inductor and the cathode of the external diode. |
| 2 | Input | input | Supply input to the collector of the high-side FET; connect to the power supply and input bypass capacitor CIN, keeping the path to GND as short as possible, with a recommended supply voltage of 8 V to 40 V. |
| 3 | CB | input | Bootstrap capacitor connection for the high-side driver; connect a high-quality 100-nF capacitor from CB to the Switch_output pin. |
| 4 | GND | power_in | Power ground pin; connect to system ground, with the CIN and COUT ground connections kept short. |
| 5 | NC | unconnected | No-connect pin; leave unconnected. |
| 6 | FB | input | Feedback sense input; connect to the feedback divider midpoint to set VOUT for the ADJ version, or connect directly to the output capacitor for fixed-output versions, with an absolute maximum pin voltage of 14 V. |
| 7 | ON/OFF | input | Enable input to the regulator; high or floating enables the regulator and low turns it off. |
| 8 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | TO-263-7 |
| Category | Power Management ICs |
| Pins | 8 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Output voltage (over line and load, 25 °C) | VOUT | 3.234 | 3.3 | 3.366 | V | VIN = 8 V to 40 V, 100 mA ≤ IOUT ≤ 3 A; TA = TJ = 25 °C | 5 |
| Output voltage (over temperature) | VOUT | 3.201 | 3.3 | 3.399 | V | VIN = 8 V to 40 V, 100 mA ≤ IOUT ≤ 3 A; over the entire junction temperature range of operation -40°C to 125°C | 5 |
| Quiescent current | IQ |  | 4.2 | 6 | mA | VFEEDBACK = 8 V for 3.3-V, 5-V, and ADJ versions | 6 |
| Standby quiescent current | ISTBY |  | 50 | 100 | µA | ON/ OFF pin = 0 V | 6 |
| Standby quiescent current (over temperature) | ISTBY |  |  | 150 | µA | over the entire junction temperature range of operation -40°C to 125°C | 6 |
| Current limit | ICL | 3.8 | 4.5 | 5.25 | A |  | 6 |
| Current limit (over temperature) | ICL | 3.6 |  | 5.4 | A | over the entire junction temperature range of operation, 40°C to 125°C | 6 |
| Output leakage current | IL |  |  | 200 | µA | VIN = 40 V, soft-start pin = 0 V; VSWITCH = 0 V | 6 |
| Switch ON-resistance | RDS(ON) |  | 0.15 | 0.17 | Ω | ISWITCH = 3 A | 6 |
| Switch ON-resistance (over temperature) | RDS(ON) |  |  | 0.29 | Ω | over the entire junction temperature range of operation -40°C to 125°C | 6 |
| Oscillator frequency (over temperature) | fO | 225 |  | 280 | kHz | over the entire junction temperature range of operation -40°C to 125°C | 6 |
| Maximum duty cycle | D |  |  | 91 | % |  | 6 |
| Minimum duty cycle | D | 0 |  |  | % |  | 6 |
| ON/OFF threshold voltage (over temperature) | VON/OFF | 0.8 |  | 2 | V | over the entire junction temperature range of operation -40°C to 125°C | 6 |
| ON/OFF input current (over temperature) | ION/OFF |  |  | 45 | µA | over the entire junction temperature range of operation -40°C to 125°C | 6 |
| Input supply voltage |  |  |  | 45 | V |  | 4 |
| Soft-start pin voltage |  | -0.1 |  | 6 | V |  | 4 |
| Switch voltage to ground |  | -1 |  |  | V | DC voltage; max printed as VIN | 4 |
| Feedback pin voltage |  | -0.3 |  | 14 | V |  | 4 |
| Soldering temperature |  |  |  | 260 | °C | Wave, 4 s | 4 |
| Soldering temperature |  |  |  | 240 | °C | Infrared, 10 s | 4 |
| Soldering temperature |  |  |  | 219 | °C | Vapor phase, 75 s | 4 |
| Storage temperature | Tstg | -65 |  | 150 | °C |  | 4 |
| Supply voltage |  | 8 |  | 40 | V |  | 4 |
| Junction temperature | TJ | -40 |  | 125 | °C |  | 4 |
| Junction-to-ambient thermal resistance (KTW, DDPAK 7-pin) | RθJA |  | 56 |  | °C/W | 7-lead DDPAK mounted horizontally, PCB area 0.136 in² of 1 oz copper (footnote 4) | 4 |
| Junction-to-ambient thermal resistance (KTW, DDPAK 7-pin) | RθJA |  | 35 |  | °C/W | 7-lead DDPAK mounted horizontally, PCB area 0.4896 in² of 1 oz copper (footnote 5) | 4 |
| Junction-to-ambient thermal resistance (KTW, DDPAK 7-pin) | RθJA |  | 26 |  | °C/W | 7-lead DDPAK mounted horizontally, PCB copper area 1.0064 in² of 1 oz copper (footnote 6) | 4 |
| Junction-to-case (top) thermal resistance | RθJC(top) |  | 2 |  | °C/W |  | 4 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | copper |  | (2) Junction to ambient thermal resistance (no external heat sink) for the 7-lead TO-220 package mounted vertically, with 0.5 in leads in a socket, or on a PCB with minimum copper area. | 5 |

## CAD (KiCad official)

- Symbol: `LM2676S-3.3`
- Footprint: `Package_TO_SOT_SMD:TO-263-7_TabPin8`
- 3D model: TO-263-7 (KiCad packages3D, STEP)
- 3D model files: `lm2676s-3-3-etched.step` / `lm2676s-3-3-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm2676s-3-3.step` / `lm2676s-3-3.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/lm2676.pdf) (41 pp, sha256 `2f3085e42097cc93`, retrieved 2026-10-30, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm2676s-3-3-datasheet.pdf)